/Engine/Source/Editor/DataLayerEditor/Public/DataLayer/DataLayerEditorSubsystem.h
Adds selected actors to the DataLayers.
true if at least one actor was added. false is returned if all selected actors already belong to the DataLayers.
bool AddSelectedActorsToDataLayers ( const [TArray](API\Runtime\Core\Containers\TArray)< [UDataLayerInstance](API\Runtime\Engine\WorldPartition\DataLayer\UDataLayerInstance) * > & DataLayers )